Train control system



July 28, 1931. r. B ODDE TRAIN CONTROL SYSTEM Filed July '29, 1926 2 Sheets-Sheet 3% A 1AM.

July 28, 193 1. 1". BODDE TRAIN CONTROL SYSTEM 2 Sheets-Sheet 2 Filed July 29, 1926 zllllllllllllhl INVENTOR. Th eodore Bodd e B g ATTORNEYS and thereby transmits adanger indication to 1the train. 7

{"When the winding mounted on the roadside body is short-circuited onitself, it gives a clear'indication. Under such conditions it serves to reflect the flux passing between the polesof the train carried magnet andfsald'.

' flux is 'practically undisturbed. The'result is thatthe' conditions of the traincarried circuit are undisturbed. In the-thirdposition a'source of energyis connected to the windingfon the roadside body; This puts the roadside" body in an inductionally repellent state which constitutes the .caution'indicationof the roadside body. In this-condition 'the'roa dside body j serves to strengthen the flux passing betweenthe'poles of the train carried'magnet when thelatter passes over a v are thereby the roadside body.- The train carried circuits dication;

The'invention will be more clearly under stood by reference to the accompanying drawingsand the'description thereof. f

In the drawings: p f i s i Figure 1 is a diagrammaticillustration of the roadside apparatusv FigureQ shows thetrain carried apparatus carried and roadside inductors.-

and-its relationship to the roadside inductor. Figure 3sh0ws a sideview of the train "Figure e shows a'modificationotthesys tern; g V a -Figure '5 shows a further modification of.

the system." I

Figure 1 shows asignallingv block and portions of the immediately preceding and next succeeding"blocks. This figure r-also shows apart of a block signalling "circuit that is commonly associated withblock sig; nals 'and for the operation thereof. Only that part of the block signalling circuit is shown herein which. cooperates with the road side inductor shown herewith.

The three-position roadside inductor which constitutes a part of the inventionto which the present 'application'is directed, consists primarily of. a body of magnetic material 10. Asshown in Figure 3, this body 10 is preferablyshaped in such a manner as to present wide pole shoes N and'S'. The body 10 is provided with a winding 11 One side of the winding 11 is connectedby'means of conductor 12 toa movable contact 13 while the other side is connectedbymeans of wire 14 to one side ofa battery'15. 'The contact 13 is movable and may be put in one of the three positions indicated. In the dotted line "position 0a shown in Figure 1, the movable contact 13 closes the circuit through the winding 11 including the battery 15. .Under such conditions the winding 11 will carry a-c-ur rent and the body 10 will be magnetized to V present'the two poles N and S as shown in Figure 3. In the b position of the contact d'isturbed'to give acaution in- 13 the. winding 11is short-circuitedby means of wire 16 without the application of'a-ny source of energy to the winding. In the 0 position of the contact 13 the winding 11' is open-circuited.

By means of the three positions which the contact 13 is capable of assuming, the inductor 10. may give anyone of three indica tions. When the contactl3 is in its 0 position and the winding llis open circuited, the body- 10 may be said to be in itsinert state and is designed to giveada'nger indication to any passing train. When the contact 13 is in the 6 position and the winding 11 is short-circuited through the wire 12 contact 13, wires '16'and 14, the roadsideinductor 10 together with'the winding 11 may be-said to be in an inductively reflective state'fandpwill "give a clear indication. When the contact 13 is in itsa position whereby anelectromotive force is impressed up on the winding 11'; .the body 10 is magnetized presentingfN- and S polesto train carried devices. The roadside inductor isth'en in an inductively repellent state and;

indicates Caution. The manner by which thesethreeindications of the roadside intions.f

" Referring to Figure lyA shows asignaling block of the railroad tracksl7 and 18., The

block is provided with a track battery 19 and the track relay 20. The block signaling circuit comprises a battery-21 pole changer 22; v V polarized control relay 23, and wires connect ing the'battery to the control relay." Theconing circuit: battery 21, pole changer 22, wire 24, track relay armature 25, wire26, control relay 23, and return wire 27. Contact 13 is a polarizedarmatureand is controlled by the 'trol relay is normally energized by the followcontrol relay 23. When the block A and the next succeeding block are unoccupied, the relay 23 isenergized' by the circuit tracedimmediately above and-the polarized armature 13 occupies the 6 position. Under suclrconditionsthe roadside inductor 10 is in its inductively'reflective state and will give a clear indication. When a train enters block A the trackmagnet 2O willbe deenergized,-its armature 25 willopen the block signaling circuit and consequently thepolarized relay 23 will be deenergiz'ed. Thepolarized contact13 will then dropto'its c position, thereby opening thecircuit ofthe winding-1'1 of the road side inductor'lO. The roadside inductonwill thereby be put into its inert state and will give a dangerindication. When the train that occupied block A passes out of block A nto the neXt succeeding block, the semaphore 1- i wieeez tenet gnel .We l ke n. 11 th rt;

ills-hitttt;

" abett w p MeerQr Y 127,; W re-2 ,1 pale q ng- 4'22 'in'm es l'npon Jtheiw'v indingll of the roadside 11139;pllt illitsiilldltrf in 1c2tti0n,,,:. .ltw llabeseee; thelderi eeshowi mind; be 1 "n blepf givui eeee yith titein 'w ieh: des gned tozcoopereteswiththeroed'side inductp ej ld to pi k-unth ed e tien g e y ther eds le inductor. 13road1y; the t train; carried indnctorfleomprises 1 t ong agne r large diaphragm of, magnetic} mater 4 ,within the field off r er etedy y them e-' netin such a-mannerthat' the diaph agm i constantly: under tension and; in distended: 4 PQ i i n--+ h v r i ;-ee rie i m gnet" 30 is. H c I ismountedon the center ofthe diaphragm-46.

This'braeketicarries two contact making e1ements'4 8giand' 49 which areelectri'cally con-' r I: nected' to thebracketx47. The receptacle 44' k eh eme er he-bi the tre nnesseebyt rQ3d$i Q inductor 1Q, P016 LMQQS N and; SK

will pass immediate y o er-thereedside f 7 are instflatedfrom eachaother and which are normally in' contact with 49 and 48 resi5e'c-j eneecliegup n the condit o Jo the madeside inductor. If themed side inductor is {in magnet or through' the diaphragm' te he der fieeted tem tsn rmelipet ee spes l urt 11 be p tt into: its etch posit-ion by; means i r semep ie ,--2 8 nto-r i ;,-sten .lie'ff' ee 22 4mm Figute mits d tt d v .124, magneti W 1 2 p 1er1zed;te n-23., I

, tion whereby the battery l53v ill he n eter h1g0,- Und r tou h iz' enditions the 19! en ll t tet end-w ll'givexe cent :1]:

:ther Q1779: ha v l he; roadside r 4, l eei ee" eting J me. the v m k; r nd t ns a ehri dicet e seere;autemet cwith" casing in a, plane parallel tothegplaneiofthe' magnet;,;;thereby dividing the casing -37 into gxthetwo chambers 38' nand 39v. The chamber 4 39 is Connected? by-means 10fconduit '41 to a: sourceof compressed air. 41A narrow air leak] irenitimny be t y. init e'ertq 9 1 11 1129 0W Emce di describe the induca rdi poseod i i and the magnet i n1Q1 ted-* n:; he train i ed ide ind nloitheflux:p s eb th eol s qf th t a car d: magnetor he-fiilf gthgat'pas e 'thr ugh'themegne ic1;

iaphragm an e es t held t indtsiten eedeor di ten ed; posi n; will b t-reti ed;

thel body f magnetic v1-, carrier Be ne e ub nt al-p rt on,of thei thebqdhlQ, Theettrege ieeinflueneee h train cemigd mggnet 511 011}; the; diaphragm i I 7 1 Will than ber-redu'ced; The tension under which the diephregmis normellyimainteii'led: 1

I intention thismovement-oat theldiaphragrn" is i utilizedteoperajte circuit making md breath,

ing deyices whichin turn control lsignaling emu-lemme re- .11.1 3 QReferrmg HOW to Flgure 2. which shows a speeific rembodiment of my invention; 31' 5 showeetreck reilcmountedyon ereilroad tie e, 32and-33Tindicatesthe wheel ofa'train passing over said track. The traincarriesgthe magnet which; may be a; strong permanent, magnet, erif desired; maybe energized bythe winding34. The magnet ispi'eferablyotthe horse shoe type of magnet having large faced legs;3,5 andg36 which are provided withpole faeesNend S. A. hermetically sealed casing-37 preferably iof nonmagnetic material ismountedon a fece of the 1egs'35 and36 in, i

such a manner as to bridge "the space between the legs. v A diaphragm 40:13 mounted in the pessage42 connects the two chambers.

Another-hermeticallygclosed.box 43 is'car f I riedbythetrain ate point away from thein-t F fluence 0;f,-,-the magnet 30.;111011 the bottom of this box is disposed the clip 'sha ped recepshaped receptacle 44 andtheachamber138 cf it the casing 37 The 'receptac1e'44 is covered wither thin diaphragfn'46z'n The/receptacle 44 fis'preferatblyrof insulating material.

-' A light bracket' 47 of conducting-material carries two spring contacts; 50a'nd 51 which tively.,

"cuits, one of said circuits being designed to" ,recelve the centronendmation and the other" *ofnsa d circuits b61119; designed to recelve -12othe stop'lindication.v The two circuitshzpve I I a rcomrnon'return. Wire 52 inwhich the'source ,of energy53is connectedby means of Wire 54; Ther'source' of energy '53 is connected to; the brecket47, The other wi're 55 of they caution receivingi circuit is "connected to the dangerreceiving circuit is connected -to a spring Contact. 51. The otherside 56 of'the pla n v mounted on the body of the magnet and i tact 50;

of element 60 leaving only an energization of element 61 produces or indicates a Hang r? 6 From what has beensaid in'an earlier porcenter of thef diaphragrn .40. -I he w'ire 59 connects the contact 58 with the spring con Theelementsoperated by the signaling cuitsiare' diagrammaticallyillustrated as 60 5 and-61, the element-61 being connected be- .10'

tween the conductors 52 and 55; fNormally elements 6.0a-nd61 are both e'nergizedand when so energized produce or indicate .a clear condition.

element 60 'producesor indicates a caution condition, and conversely, the deenergization condition. r g I The operationof thesystemshown in Figures I, 2 and 3 is as'foll'ows: The compressed air o'f-the air brake system is allowed to enter chamber 39 of casing 37'tothe right ofthe iron membrane- This compressed air leaks into chamber'BS throughthe narrow air leak passage; connecting the; two chambers. The compressed-air therefore 'passed by fneans of;

theflexible connection 45' into thereceptacle; I arrow air "leak passage mentof thediaphragm46 downwardly, with 44 and through the) 701mm the box434 "tion' of this specification, thefoperati'on "of thesy'stem shown in Figures l'to 3"w ill'be' apparent. Assuming that the blockjA and the block ahead are unoccupied, the contact- '13 will occupy its bi-position and the wind ingjll will be short-circuited, and. the in-1 .ductor will give a'clear indication. Asthe train passes over the inductorlO and the poles of the magnet pass over the poleso f the inductor .10, the inductor will serve-to reflect the flux conditions that exist between the poles 'and'3 6 and the diaphragm 4:0 and ever, the block A'is occupied and the polar-- ized control relay 23 "is deenergized, the'con so will retain its normal position and the "normally closed caution. and danger indication circuits will not be operated. If, howtact 13 will'occupy .itsc-"position and the f winding 11, will be open-circuited' The inductor l O'is now in its inert condition a nd I train magnet 30-reaches a position overlying V I the inductor-l0, the flux passing between the When the will give a danger indication.

T-legs' 35 and 36 and passing through the diaphragm 40 will be partly'defiected through I the inductor 10 with the result that'the attractive'infiuence of the magnetupon the I dia-phragm- 40 will be lessened and the diaphragm 40 will retract from theposition 'shownto a position to theleft thereof. This j sudden contractionofthediaphragmAO will cause an impulse to be transmitted through the tubing 71 to the. diaphragm 456. In view ofthe factthatthe diaphragm 46is several The deenergization oii V element 61 leaving only the energization oI 15 to the air brake system. I"

' tacts 49, 50.

times'smallenthan the diaphgram' 40, the

movement of s'aiddiaphragm 46'will be con-V.

moved upward. "This will result in the breakingpfthe danger circuit between the contacts L9 'and'50 and the operation of the indicator 'produc1ng a danger indication.

1 If, however, the block A is unoccupiedjand thenext- -'succeeding block is occupied, the pole changer 22 will occupy'its dotted line,

position and the control relay 23 will be energizedin the reverse direction. ;The contact 13 will then occupy its a'position and themductor 10 will be energized by the battery 15 and windingill. Whenthe train under these conditionsv reaches position wherein the train magnet overlies the inductorl0, the in.-

fluence of the magnetic fiuxcreated by the inductor 10 will be such as to strengthen the 'fiux passingibetween the legs 35 and 36 ofthe train carried magnet,.and will strengthen the flux passing through the diaphragm 4:0 with the result that the influence of'the magnet upon the 'jdiaphr'agm"will'be increased and the latter will be moved toa moredistended position to theright oi the normal position.

This sudden 1 distension of Ithe'diaphragm. 40'

will'cause'a correspondingly magnified movethe result that the caution indication circuit willQbe broken between the contacts 48 and 51, and the'indicatorfil alone will be operated producing, a caution condition. The

contacts 57 58 are not essential to the operation of the system. They are inserted, howair in chamber 89 will, force the diaphragm 40to the left'an'd the danger indication cirouit will be open between the contacts 57, 58. i If a leak occurs in theair chamber'39 on the right of the diaphragm, it can do no harm to the system if the leak'is small as the-air pressure will still be considerable. If, how,-

ever, the leak in theair chamber 39 isof such a size as to reducethe air pressure therein. to.

a considerable extent, the 'trainwill be automatically stopped in the same way and by the samemeans asoare provided insystem's whereln shoe stems operable by alr pressure "are utilized in connection with ramp systems that is to say, the said chamber is connected If a leak to altmosphereoccurs in the hermetically closed box 43, the pressure below the thin diaphragm 46 willibe greater than the pressure'above the thin diaphragm and danger indication circuit betweenthe con- 1 While it is not essential :for' the operation of this system that compressed air be utilized this fact will bring about an opening of the p three.indications%ofth I Clear, caution anddengefi It 1s bvlol zthat.

v ge mmsf andjwhileatmospheric air maybe utilized in thesystem,jl prefer to .usecompressedair for the reason that it constitutes abetter medium, ifor transmitting the pressure Wave: from the; i phr g so toth i ph agm 4 -2, T t transmission will be much; strongerby means 7 ,of compressed air than when atmospherieair 1 V .tionsof,thelbrakes onthe train),-

is utilizedv z I The danger indicfltorfil may' be of any typei desired and-s may be of the Wellknowntype wherein its operationeilectuates the applica- While I haize-shovvngthatthecontact13 maybe operated by h rp la iz ,re ay 23a it is obvious that the samelcontaetimay be opera ed bythe s maphor 2- The i om phore' 2is hetype that isco v n ly u edo in block signal ing i ystem15 and s. 1 de g e o give thr indi ations by thexth e ifierant positions o .the semaphore; arm, The} e s maph farm. a

i the .contact 13" may befso -COI nected ,tothe c semaphore oarmi that in its clear positionthe circuit-of the =s;vvinding, 11' Will be shorte n cuited Lon itself, j in the CilllllilQIl POSlhlOll; of the semaphore arm the windingill may be connected through a battery and in the danger position of, the semaphore arm: the Winding ll maybeconnectedthrougha battery and n the danger position ofthe semaphore arm thevvvinding 11' may beopen-clrcu i-ted, ,s ;,Figure 4 'ofgthe drawings shows a mod ificationi of the, system-in which the roadside inductor is capableof'giving onl'ytwo'ine dications, namely, :the indications oi; clear and danger. The battery 15-may be omitted in this systemxif desired'. The roadsideinductor will under :theseconditions give a gclear indicatiOn Wh-en .the- Winding .11 is short-ieircuited,i and ,.Will give a danger in Q dication WheIrthe'r'Wi-nding ;;1 1 is ;0p,e n;-ci rv-- ,jcuited; altv islobviouaohowever, that if de cal withx those I V sired the clear indication ziriay :be :giyen by inserting a-sourceof energy 'm'the c rcuit two 'contacts'49, 50 are in the danger; receivi ingcircuit which is-idei1tical with the da ger receiving circuitjsho'vvnin 2.- Z'In this i tema, f rea dan er. a on. Wi he picked upihy'fthe' train when it passes the} t roadside *indu'c'tor 'underf such "conditions when thewinding o-fthe 'ioadside inductor is;open-circuited}; v Ifjthe Winding of the i l roadside inductor is short-circuitedor isfleon 65' nected to a sourceof venergy, theiinductor gives aclear indication and the train: car} riedi circuit-Will not be disturbed Whenthe conditions; o flFigurejS shows-system, similar to that shownin' Figure4:;except-that instead of V utilizing compressed air for transmitting the v train passes over the inductor 'underfsuch impulsefrom the large diaphraginAO to the 1 r small {diaphragm 4:6,,a'ir at atmospheric pres-f sureis utilizeclffor the same purpose! The construction and arrangement of the; train carried devices in this system aresubstantiallyidentical with that shown in'l igureh except that the box a3 is eliminated and the contaets57 and 58,- which are designed in the eliminated. Otherwise; the system shown in igure ,5 operates in the same manneras In a train control system, in'combina-' tronwlthavehicle carried inductoryaf roadside three position apparatus: comprising an" element of magnetic material for giving a danger indication when in its inert state,

a Winding on said element and circuit means for said winding forfim-parting to said:-ele-' ment'an inductively reflective state togivea clear indication and for imparting to said a caution indication. r I,

- 2.: In a train control system, in combination with a Vehicle carried inductor; a road elementan indueti-velyirepulsive state to g'iwe side three position indicator coinprising t anjelem-ent ofmagnetic material, aqwinch ing on saidelernent; a circuit for said wind ing,' and selective switch means for short cin" culting said winding and for connectinga source-of energy tosaid Winding.

i a In a train control system, in I combina;

t ion with a vehicle carried induct-013 a roa'd- 1 side three position indicator'comprising an" e element of magnet c mater-ial, a. winding on saidelement, a circuit for said "winding;

and selective switch means operable in ac-I 'cordance with" track conditions for short cir cuitlng said Wmdmg'and for coiinectlng a' source of energy to said Winding.

4. 111 a train control system, in :co'mbina tion with a vehicle carried inductor, a" road side. three position indicator comprising, an} I I element l of magnetic material, a Winding yen said element, a cireu'it for said wi ding n a f selectiveswlteh means respons ve to track conditions for short circuiting said Winding Winding.

In" an inductive railway signaling sys- 7 tom, a magnet, a signaling circuit, a difa-f' phrag-m held undertheinfluenceof the maga net, andpneuinatic' means controlled the diaphragm' whereby a fvariation in the mag-J netic flux betWeen thepol'es o'flthe'imagnet 1 will open the signaling circuit." f-

so preceding systems to give .a danger indica+ition in case of a'leak 1n the system; arealso I andforgconnecting asource of-energydto said- Q under the influence of the device, a second.

diaphragm, and a bodyof compressed fluid connecting thediaphragms. V o 13; In an inductive railway signaling sys-- 7 tem, an inductiondevice,a diaphragm held r under-.theinfiuence of the device, a second an inductive railway signaling system, a magnet-,a normally closed signaling circuit, 'a' diaphragm of magnetic material mounted on the'poles of the magnet and pneumatio'means whereby a movement of cuitg I Y 7. .In aninductive railway signaling systhefdiaphragm willopen the signaling cirtem, an'induction device, a normally closed signaling circuit, adiaphragm under tension held under the influence Lof the induction device, and pneumatic means whereby a movenalingcircuit; I p v v v 8. In an; inductive railway signaling sys tem, an induction device, a diaphragmjheld underJthe influenceof the device, a second diaphragm heldaway front the influence of the induction device. and'meansrwhereby a movement of the first diaphragm will cause phragm.

a corresponding movement in: the second dia- 9.. In an inductive railway signaling sys} diaphragm held awayfmm the influence of the induction device and means whereby a movement of the first diaphragm-will cause a correspondingmagnified movement in the second diaphragm, r V

' 10.- In aninductive railway signalingsystem, an induction device, a diaphragm held under the influence of; the device, a. second diaphragm held away from theinfiuence of r the inductiondeviceand pneumatic means wherebyia movement of the first diaphragm will. cause a corresponding movement in the second diaphragm.

, under ,the" influenceofthe'device', a second diaphragm, and a body of fluid, connecting the diaphragms; o v

12. In an inductive railway signaling system, an induction device, a diaphragm held tem, aniinduction device, a diaphragm "held under-theinfiuence of the device, ajfsecond' 1 diaphragm held away ;fif'om .theinfiuence of the inductiondevice', means whereby a1move-- ment of th'efirs't' diaphragm will cause a corresponding movement ,in, the second diaphragm and circuit making and breaking means operableby the movement of the second diaphragm. I

lhIn aniinductive. 'ailway signaling tem,. aninductiondevice, a diaphragm heldunder thej influence of the device, a second tem, a danger, signal circuit on theE-train', a 1

caution signal circuit oni thetrain, a inagnet carried by'the train, and pneumatic means whereby 'a variation o f the magnetic flux. in the space'betw'eenthe pol'es will operate said circuits selectively. W

' 16. In an inductive railway signaling sysem; a normally closed danger 'signal circuit on the train, a normally closed caution signalcircuit onthe train, a magnet carried'by the train, a diaphragm held; under the influence ofthe magnet, and means whereby a 7 movement ofthe" diaphragm will open id circuits selectively'g q a 17. In an inductive railway sign a'lingsys} tein,'anormally closed dangersignal circuit 4 onthe train, .a norinallyclosedcaution signal circuit onthetrain, a magnet carried by the train, a. diaphragm held under the influence of the magnet, and pneumatic means whereby a movement of the diaphragm will open said circuits selectively. 1 I

' 1-8. In an inductive railway signaling 'system,a danger signalcir'euit on the train, a caution signal circu t on'tlie train, an induc tion device carriedby the train, a diaphragm held-under-tlie influence of the device, a second diaphragm, and circuit making and 1 breaking means operable-by the second diaphragm whereby one of said circuits. is

opened while the other is maintained closed.

19. Thecombination of a magnet,a casing I mounted on the poles of said magnet, and a diaphragm mounted in said casing, whereby a portion at least of saiddiaphragm may be moved-by a variation in the magnetic flux 7 o passing betweenthe poles or themagnet. I v 11-. In aninductive railway signaling system, an induction device, a diaphragmheld 20. Thecombinationof a magnet, a casing mounted on the poles of said-magnet, a diaportion at least of saiddiaphragm maybe moved by a 'variation I in i the :inagrietic flux "phragminountedin said casing, whereby a passing between the polesof the'magnet, and 1 circuit-making and breaking means operable by the movement of aid,di h g p i g 1 21. In a train control system, the combination of two diaphragms,a traincont'i'o-lling magnet for vibrating one of said diaphragms I I a 3 dy of fiuidconnecting thetwo dia;

phragm are t'ransmittedtd theiother. r w

,phragm whereby the vibrations-ofone -dia'- 22. In a railway signaling system,*a mag net, a diaphragm held under tension b-ysaid magnet, and roadside apparatus iot selectively reducing or increasing the tension:

23. In a railway signalingsystem,amagg net,a diaphragm disposed within the field of; force of saidinagneaand roadside apparatus for selectively increasing :or decreasing said 1 field of force. 1 1

.24; Inia railway signaling system, aftrainj, I,

carried magnet, and roadside apparatus for selectively increasing, ids creasing or I main-x @dNiajgara and State of New Y ork,-this Qth day -taining the flux passing between the poles of themagnet. 1 p v 25. In a railway signaling'system, a train" carried magnet, and roadside apparatus operable-jin accordance with track conditions.

' [for selectively increasing, decreasing or .7 maintaining the flux poles of the magnet. 7

container, and means whereby aleak in said i o .jcontainer will "#29. In an induction railway signalling systern, a train carried magnet;a hermetically Y sealed container mounted onthe magnet, an

tive apparatus;

passing; between the 26, In a railway signalling system, a train" carried magnet, and roadside apparatus rejsponsive to track conditions for selectively I increasing, decreasingfor' maintaining "the 3 I flux passingbetweenthe poles of the magnet.

27; In an induction railway signallingsya jtem', a train carried I'nagnet, a diaphragm'dis- [posedwithin the attractive influence of the magnet, a roadside inductive apparatus-for giving a plurality of indications, and means whereby the attractive'infiuence of the magnet on the diaphragm is selectively varied in accordance With theindication of the induc- 2* 28. In an induction te'm, a train carriedmagnet, a hermetically sealed-container mounted onsaidmagnet, ax g i' dlaphragm mounted 111 said "container, a

source of compressed fluid connected to said I give a danger indication on the train;

otherhermetically sealed container, a passage containing compressed air connecting the two 1 containers, and means whereby aleak 1n the 7 second container will give a danger 1nd1ca tion.

Signed at Niagara F alls, in thecounty of my A. b.1926.

railway signallingsysa I {THEODORE BODDE. 

